Ecological survey of Saccharomyces cerevisiae strains from vineyards in the Vinho Verde Region of Portugal

One thousand six hundred and twenty yeast isolates were obtained from 54 spontaneous fermentations performed from grapes collected in 18 sampling sites of three vineyards (Vinho Verde Wine Region in northwest Portugal) during the 2001-2003 harvest seasons. All isolates were analyzed by mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) and a pattern profile was verified for each isolate, resulting in a total of 297 different profiles, all revealed to belong to the species Saccharomyces cerevisiae. The strains corresponding to seventeen profiles showed a wider temporal and geographical distribution, being characterized by a generalized pattern of sporadic presence, absence and reappearance. One strain (ACP10) showed a more regional distribution with a perennial behavior. In different fermentations ACP10 was either dominant or not, showing that the final outcome of fermentation was dependent on the specific composition of the yeast community in the must. Few of the grape samples collected before harvest initiated a spontaneous fermentation, compared to the samples collected after harvest, in a time frame of about 2 weeks. The associated strains were also much more diversified: 267 patterns among 1260 isolates compared to 30 patterns among 360 isolates in the post- and pre-harvest samples respectively. Fermenting yeast populations have never been characterized before in this region and the present work reports the presence of commercial yeast strains used by the wineries. The present study aims at the development of strategies for the preservation of biodiversity and genetic resources as a basis for further strain development.ENOSAFE - (Nº 762, programa AGRO, 657 C2

Survey of molecular methods for the typing of wine yeast strains

A survey of the genetic polymorphisms produced by distinct methods was performed in 23 commercial winery yeast strains. The microsatellite typing, using 6 different loci, an optimized interdelta sequence analysis and RFLP of mitochondrial DNA generated by the enzyme Hinf I had the same discriminatory power: among the 23 commercial yeast strains, 21 distinct patterns were obtained. Karyotype analysis originated 22 patterns, thereby allowing the discrimination of one of the three strains that were not distinguished by the other methods. Due to the equivalence of the results obtained in this survey, any of the methods can be applied at the industrial scale.Fundação para a Ciência e a Tecnologia (FCT) - POCTI/BIO/38106/2001 (Eixo 2, Medida 2.3, QCAIII - FEDER).Instituto de Cooperação Científica e Tecnológica Internacional (ICCTI) - grant nº 657 C2.Comunidade Europeia (UE) - contract number QLK4-CT-2001-51873

Genetic Diversity and Population Structure of Saccharomyces cerevisiae Strains Isolated from Different Grape Varieties and Winemaking Regions

We herein evaluate intraspecific genetic diversity of fermentative vineyard-associated S. cerevisiae strains and evaluate relationships between grape varieties and geographical location on populational structures. From the musts obtained from 288 grape samples, collected from two wine regions (16 vineyards, nine grape varieties), 94 spontaneous fermentations were concluded and 2820 yeast isolates were obtained that belonged mainly (92%) to the species S. cerevisiae. Isolates were classified in 321 strains by the use of ten microsatellite markers. A high strain diversity (8–43 strains per fermentation) was associated with high percentage (60–100%) of fermenting samples per vineyard, whereas a lower percentage of spontaneous fermentations (0–40%) corresponded to a rather low strain diversity (1–10 strains per fermentation)

Association between Grape Yeast Communities and the Vineyard Ecosystems

The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Acores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viti-cultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.Joao Drumonde Neves is the recipient of a fellowship of the Azorean Government (M321/006/F/2008) and PROEMPREGO. This work was supported by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds through FCT by the projects FCOMP-01-0124-008775, PTDC/AGR-ALI/103392/2008 and PTDC/AGR-ALI/121062/2010.info:eu-repo/semantics/publishedVersio

Potential for a Circular Autopoietic Economy on Canavese Territory

The aim of this gigamap is to describe and summarize a student work carried out during the semester course Open Systems Design at Politecnico Torino. The map is one of the outputs from an analysis of the Canavese, Piedmont region and subsequently an in-depth study of the relationships and “flows” with certain “currencies” between some selected economic and public actors. Canavese is a historical-geographical area located in the province of Turin, Italy; it’s full of great natural and geological spots, with a strong enogastronomic identity, historical re-enactments, a well-known manufacture sector like the ceramic of Castellamonte, as well as the leading high-tech branch like Arduino. Through the approach deriving from systemic design, it was possible to identify some strategies for the creation of new networks aimed at transforming the economy and production processes from linear to circular approach. Five types of “circular flows” were assessed and “designed into” the current linear system, thus proposing an improved economy based on circularity: flows of matter (energy/CO2, water, materials), economic flows, and social flows. The Gigamap will be presented to stakeholders in a public hearing and supposedly be used to illustrate and incubate a circular economy that is more resilient and more regenerative. Reading the map The reading should start at the top left, where the abstract is located, next, there is an outline that shows the connections between the five topics investigated. Subsequently, there is a timeline with some fundamental events in the history of the Canavese. In the center there is the circularity map with the main cities, focusing on new opportunities of circular flows between the 15 analysed economic actors. At the bottom, some general data and on the right a brief description of the role and territorial qualities of the companies. Lastly, there is a summary of the emerging properties

Mise en forme des thermoplastiques chargés de nanotubes de carbone : application à la microinjection de Polyamide 12

Addition of multi-walled carbon nanotubes (MWNT) into a polymer matrix of polyamide 12(PA 12), typically an electrical insulator, can make the whole system electrically conductor. Thearrangement of MWNT in conduction pathways would be the responsible for the conduction ofelectrical charges through the material. Electrical conductivity on isotropic nanocomposites may reach an asymptotic value (~10-2 S.m-1) for MWNT content above 1,2 wt% MWNT (percolation threshold). In microinjection molding, high shear rates (~104 s-1) as well as severe temperature gradient are imposed to the nanocomposite leading to specific microstructures which determine at the same time the electrical properties. In this work, we were interested in studying the evolution of MWNT microstructure inside the melt PA 12 matrix (by rheological tests coupled withdielectric properties measurements) under particular shear rates (from 0,02 to 1 s-1) and coolingrate (3 °C.min-1) conditions. Besides, a total loss of conduction pathways in the normal direction to the flow plane is revealed when measuring the electrical conductivity on the microinjected samples. Moreover, a reduction of the in-plane conductivity was observed in comparison with the isotropic samples. Previous results suggest an arrangement in the form of weakly oriented MWNT clusters which was confirmed by the wide orientation distribution determined by Raman spectroscopy. In fact, during microinjection molding, initial MWNT aggregates would be broken into disconnected smaller ones which could explain the generalized loss of electric properties and the almost isotropic microstructure revealed at the macro and micro scale.L'addition de nanotubes de carbone multiparois (MWNT) dans une matrice de polyamide 12 (PA 12), électriquement isolante, permet d'augmenter les propriétés électriques vers un comportement conducteur. Cette modification est influencée par l'arrangement des MWNT en chemins de conduction qui permettent le transfert des charges électriques entre deux électrodes. La conductivité électrique des nanocomposites isotropes atteint une valeur asymptote (~10-2 S.m-1) pour des teneurs supérieures à 1,2% en masse (seuil de percolation électrique). En microinjection, les nanocomposites sont soumis à des taux de cisaillement très élevés (~104 s-1) et des gradients de températures extrêmes, qui conditionnent fortement la microstructure et les propriétés électriques de pièces mises en forme par ce procédé. Cette thèse a eu pour but d'expliquer l'influence de la vitesse de cisaillement (0,02 s-1 - 1 s-1) et la vitesse de refroidissement (3 °C.min-1) sur l'évolution des propriétés électriques du nanocomposite PA12/MWNT. L'analyse de ces propriétés a permis de déduire, à l'état fondu, l'évolution de l'arrangement de MWNT dans cette fenêtre de conditions. Dans les pièces microinjectées, nous constatons une perte complète du comportement conducteur dans la direction normale au plan d'écoulement et une chute de la conductivité dans les directions d'injection et transverse. Ces faits suggèrent alors un arrangement en forme d'agrégats faiblement orientés dans le plan d'écoulement, qui est corroboré par la très large distribution d'orientation déterminée par l'analyse en spectroscopie Raman des pièces micro-injectées. Lors du procédé de microinjection, les agrégats de MWNT seraient alors cassés dans des agrégats plus petits, mais fortement déconnectés les uns des autres, expliquant ainsi la chutedes propriétés électriques mais aussi l'observation d'une microstructure quasi isotrope à l'échelle macro et micro

Mise en forme des thermoplastiques chargés de nanotubes de carbone : application à la microinjection de Polyamide 12

Addition of multi-walled carbon nanotubes (MWNT) into a polymer matrix of polyamide 12(PA 12), typically an electrical insulator, can make the whole system electrically conductor. Thearrangement of MWNT in conduction pathways would be the responsible for the conduction ofelectrical charges through the material. Electrical conductivity on isotropic nanocomposites may reach an asymptotic value (~10-2 S.m-1) for MWNT content above 1,2 wt% MWNT (percolation threshold). In microinjection molding, high shear rates (~104 s-1) as well as severe temperature gradient are imposed to the nanocomposite leading to specific microstructures which determine at the same time the electrical properties. In this work, we were interested in studying the evolution of MWNT microstructure inside the melt PA 12 matrix (by rheological tests coupled withdielectric properties measurements) under particular shear rates (from 0,02 to 1 s-1) and coolingrate (3 °C.min-1) conditions. Besides, a total loss of conduction pathways in the normal direction to the flow plane is revealed when measuring the electrical conductivity on the microinjected samples. Moreover, a reduction of the in-plane conductivity was observed in comparison with the isotropic samples. Previous results suggest an arrangement in the form of weakly oriented MWNT clusters which was confirmed by the wide orientation distribution determined by Raman spectroscopy. In fact, during microinjection molding, initial MWNT aggregates would be broken into disconnected smaller ones which could explain the generalized loss of electric properties and the almost isotropic microstructure revealed at the macro and micro scale.L'addition de nanotubes de carbone multiparois (MWNT) dans une matrice de polyamide 12 (PA 12), électriquement isolante, permet d'augmenter les propriétés électriques vers un comportement conducteur. Cette modification est influencée par l'arrangement des MWNT en chemins de conduction qui permettent le transfert des charges électriques entre deux électrodes. La conductivité électrique des nanocomposites isotropes atteint une valeur asymptote (~10-2 S.m-1) pour des teneurs supérieures à 1,2% en masse (seuil de percolation électrique). En microinjection, les nanocomposites sont soumis à des taux de cisaillement très élevés (~104 s-1) et des gradients de températures extrêmes, qui conditionnent fortement la microstructure et les propriétés électriques de pièces mises en forme par ce procédé. Cette thèse a eu pour but d'expliquer l'influence de la vitesse de cisaillement (0,02 s-1 - 1 s-1) et la vitesse de refroidissement (3 °C.min-1) sur l'évolution des propriétés électriques du nanocomposite PA12/MWNT. L'analyse de ces propriétés a permis de déduire, à l'état fondu, l'évolution de l'arrangement de MWNT dans cette fenêtre de conditions. Dans les pièces microinjectées, nous constatons une perte complète du comportement conducteur dans la direction normale au plan d'écoulement et une chute de la conductivité dans les directions d'injection et transverse. Ces faits suggèrent alors un arrangement en forme d'agrégats faiblement orientés dans le plan d'écoulement, qui est corroboré par la très large distribution d'orientation déterminée par l'analyse en spectroscopie Raman des pièces micro-injectées. Lors du procédé de microinjection, les agrégats de MWNT seraient alors cassés dans des agrégats plus petits, mais fortement déconnectés les uns des autres, expliquant ainsi la chutedes propriétés électriques mais aussi l'observation d'une microstructure quasi isotrope à l'échelle macro et micro

Mise en forme des thermoplastiques chargés de nanotubes de carbone (application à la microinjection de Polyamide 12)

L'addition de nanotubes de carbone multiparois (MWNT) dans une matrice de polyamide 12 (PA 12), électriquement isolante, permet d'augmenter les propriétés électriques vers un comportement conducteur. Cette modification est influencée par l'arrangement des MWNT en chemins de conduction qui permettent le transfert des charges électriques entre deux électrodes. La conductivité électrique des nanocomposites isotropes atteint une valeur asymptote (~10-2 S.m-1) pour des teneurs supérieures à 1,2% en masse (seuil de percolation électrique). En microinjection, les nanocomposites sont soumis à des taux de cisaillement très élevés (~104 s-1) et des gradients de températures extrêmes, qui conditionnent fortement la microstructure et les propriétés électriques de pièces mises en forme par ce procédé. Cette thèse a eu pour but d'expliquer l'influence de la vitesse de cisaillement (0,02 s-1 - 1 s-1) et la vitesse de refroidissement (3 C.min-1) sur l'évolution des propriétés électriques du nanocomposite PA12/MWNT. L'analyse de ces propriétés a permis de déduire, à l'état fondu, l'évolution de l'arrangement de MWNT dans cette fenêtre de conditions. Dans les pièces microinjectées, nous constatons une perte complète du comportement conducteur dans la direction normale au plan d'écoulement et une chute de la conductivité dans les directions d'injection et transverse. Ces faits suggèrent alors un arrangement en forme d'agrégats faiblement orientés dans le plan d'écoulement, qui est corroboré par la très large distribution d'orientation déterminée par l'analyse en spectroscopie Raman des pièces micro-injectées. Lors du procédé de microinjection, les agrégats de MWNT seraient alors cassés dans des agrégats plus petits, mais fortement déconnectés les uns des autres, expliquant ainsi la chutedes propriétés électriques mais aussi l'observation d'une microstructure quasi isotrope à l'échelle macro et microAddition of multi-walled carbon nanotubes (MWNT) into a polymer matrix of polyamide 12(PA 12), typically an electrical insulator, can make the whole system electrically conductor. Thearrangement of MWNT in conduction pathways would be the responsible for the conduction ofelectrical charges through the material. Electrical conductivity on isotropic nanocomposites may reach an asymptotic value (~10-2 S.m-1) for MWNT content above 1,2 wt% MWNT (percolation threshold). In microinjection molding, high shear rates (~104 s-1) as well as severe temperature gradient are imposed to the nanocomposite leading to specific microstructures which determine at the same time the electrical properties. In this work, we were interested in studying the evolution of MWNT microstructure inside the melt PA 12 matrix (by rheological tests coupled withdielectric properties measurements) under particular shear rates (from 0,02 to 1 s-1) and coolingrate (3 C.min-1) conditions. Besides, a total loss of conduction pathways in the normal direction to the flow plane is revealed when measuring the electrical conductivity on the microinjected samples. Moreover, a reduction of the in-plane conductivity was observed in comparison with the isotropic samples. Previous results suggest an arrangement in the form of weakly oriented MWNT clusters which was confirmed by the wide orientation distribution determined by Raman spectroscopy. In fact, during microinjection molding, initial MWNT aggregates would be broken into disconnected smaller ones which could explain the generalized loss of electric properties and the almost isotropic microstructure revealed at the macro and micro scalePARIS-Arts et Métiers (751132303) / SudocSudocFranceF

Influence of temperature on dielectric properties of PA-12/CNT composites

International audiencePolyamide12 (PA12)/multiwalled nanotubes (MWNT) composites were characterized in terms of complex permittivity and conductivity. Measurements were achieved on a LCR meter in a frequency range between 102 and 106 Hz. Samples were placed between plate-plate geometry electrodes and heated at temperature higher than melt temperature. Electrical and dielectric properties show different behaviours depending of the MWNT content, implying that different conduction mechanisms are involved

Déprimage: Définition

National audienceEarly spring grazing is an early grassland management type done by grazing. It is usually conducted on hay meadows as soon as the grazing starts and may have different purposes. Concerning pasture, it allows to extend the grazing season by gathering young grass on the earliest areas at low cost. As regards mowing, it helps maintain the quality of hay by putting off the developing stage of the grass in order to position the hay-making stage in a more favourable weather window. Early spring grazing consists in cutting the upper part of the grasses, keeping the future ear (reproductive meristem) rising in the stem...Le déprimage est un mode d’exploitation précoce des graminées par le pâturage. Il est généralement conduit sur prairie de fauche, par pâturage, dès la mise à l’herbe et peut avoir des objectifs différents. En pâturage, il permet d’allonger la saison de pâturage en allant chercher de l’herbe jeune à faible coût sur les surfaces les plus précoces. En fauche, il permet de maintenir la qualité des foins en repoussant le stade de développement de l’herbe pour positionner la fenaison dans une fenêtre météo plus favorable. Sur céréales d’hiver, il améliore le tallage et peut permettre une augmentation de rendement..